diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/cryptography/hazmat/backends/openssl/rsa.py | 18 | ||||
| -rw-r--r-- | src/cryptography/hazmat/primitives/asymmetric/padding.py | 12 |
2 files changed, 19 insertions, 11 deletions
diff --git a/src/cryptography/hazmat/backends/openssl/rsa.py b/src/cryptography/hazmat/backends/openssl/rsa.py index 63ba6273..a85f7da1 100644 --- a/src/cryptography/hazmat/backends/openssl/rsa.py +++ b/src/cryptography/hazmat/backends/openssl/rsa.py @@ -15,22 +15,18 @@ from cryptography.hazmat.primitives.asymmetric import ( AsymmetricSignatureContext, AsymmetricVerificationContext, rsa ) from cryptography.hazmat.primitives.asymmetric.padding import ( - AsymmetricPadding, MGF1, OAEP, PKCS1v15, PSS + AsymmetricPadding, MGF1, OAEP, PKCS1v15, PSS, calculate_max_pss_salt_length ) from cryptography.hazmat.primitives.asymmetric.rsa import ( RSAPrivateKeyWithSerialization, RSAPublicKeyWithSerialization ) -def _get_rsa_pss_salt_length(pss, key_size, digest_size): +def _get_rsa_pss_salt_length(pss, key, hash_algorithm): salt = pss._salt_length if salt is MGF1.MAX_LENGTH or salt is PSS.MAX_LENGTH: - # bit length - 1 per RFC 3447 - emlen = int(math.ceil((key_size - 1) / 8.0)) - salt_length = emlen - digest_size - 2 - assert salt_length >= 0 - return salt_length + return calculate_max_pss_salt_length(key, hash_algorithm) else: return salt @@ -220,8 +216,8 @@ class _RSASignatureContext(object): pkey_ctx, _get_rsa_pss_salt_length( self._padding, - self._private_key.key_size, - self._hash_ctx.algorithm.digest_size + self._private_key, + self._hash_ctx.algorithm, ) ) self._backend.openssl_assert(res > 0) @@ -348,8 +344,8 @@ class _RSAVerificationContext(object): pkey_ctx, _get_rsa_pss_salt_length( self._padding, - self._public_key.key_size, - self._hash_ctx.algorithm.digest_size + self._public_key, + self._hash_ctx.algorithm, ) ) self._backend.openssl_assert(res > 0) diff --git a/src/cryptography/hazmat/primitives/asymmetric/padding.py b/src/cryptography/hazmat/primitives/asymmetric/padding.py index c796d8e4..a37c3f90 100644 --- a/src/cryptography/hazmat/primitives/asymmetric/padding.py +++ b/src/cryptography/hazmat/primitives/asymmetric/padding.py @@ -5,11 +5,13 @@ from __future__ import absolute_import, division, print_function import abc +import math import six from cryptography import utils from cryptography.hazmat.primitives import hashes +from cryptography.hazmat.primitives.asymmetric import rsa @six.add_metaclass(abc.ABCMeta) @@ -65,3 +67,13 @@ class MGF1(object): raise TypeError("Expected instance of hashes.HashAlgorithm.") self._algorithm = algorithm + + +def calculate_max_pss_salt_length(key, hash_algorithm): + if not isinstance(key, (rsa.RSAPrivateKey, rsa.RSAPublicKey)): + raise TypeError("key must be an RSA public or private key") + # bit length - 1 per RFC 3447 + emlen = int(math.ceil((key.key_size - 1) / 8.0)) + salt_length = emlen - hash_algorithm.digest_size - 2 + assert salt_length >= 0 + return salt_length |